XRF analysis of glass beads from the Mycenaean palace of Nestor at Pylos,Peloponnesus, Greece: new insight into the LBA glass trade

In recent years there has been a growing interest in Mycenaean glass among archaeologists and scientists. Scholars have traditionally thought that all Mycenaean glass was imported either in finished form or as ingots and simply shaped or worked at the Mycenaean sites. Chemical studies of other Mycenaean glass (50 and 43) support the hypothesis that glass was imported into Mycenaean Greece, but there is also indication for glass production in mainland Greece at the palace of Thebes (Nikita and Henderson, 2006). There is no evidence for glass making or working at the Palace of Pylos, yet there is an abundance of glass beads there. The aim of this paper is to identify the technology and source for the glass of these beads and thus to ascertain how Pylos was connected to the broader Mycenaean and Mediterranean economies. The composition of the glasses was determined by means of portable XRF analysis and compared to that of other Late Bronze Age glasses from Egypt, Mesopotamia and mainland Greece. Four blue beads coloured with cobalt and one blue bead coloured with copper have Ti and Zr compositions consistent with an Egyptian origin of manufacture while five other beads show Ti and Zr concentrations consistent with a Mesopotamian origin (Shortland et al., 2007). Based on the dearth of Egyptian and Mesopotamian imports in Pylos, the presented data support the hypothesis that Pylos was receiving via internal Greek trade routes foreign-produced glass, which may have been worked abroad or in Greece.     

Potash - a key raw material of glass batch for Bohemian glasses from 14th-17th centuries?

The aim of this work is to verify or refute hypothesis of existence of basic/universal glass batch: quartz sand: potash: limestone, at a ratio of 2: 1: 1 used in Bohemian glass production since the middle ages onwards and to simulate the preparation of a potassium glass type with the composition used in medieval Bohemia. The chemical composition of Bohemian glass, which incorporated in the proposed glass batch for glassmaking on a laboratory scale, was evaluated by (a) findings directly related to glassmaking (samples from glasswork in Moldava dating back to the 15th century) and (b) information from publications.Experimentally produced glasses for the present paper were prepared from raw materials such as ash, leached ash, potash, limestone and quartz sand. The plant raw materials (spruce, beech and bracken ashes, raw and refined potash) were treated and prepared by methods similar to the production procedures used in the pre-industrial era.The main contrast was found in the CaO/K₂O weight ratio, which was determined in glasses that were characteristic of given periods. While this ratio was often below 1 in glasses of the 15th century, it reached values above 1 in glasses at the turn of the 16th-17th centuries. This result may indicate that the composition of the glass batch had changed.The results of the present study reject the current scholarly work dealing with glass batch composition during the 14th-17th centuries and confirm that glass produced in some Bohemian medieval glassworks could have been melted from a batch that included plant ash, making the use of limestone unnecessary. The traditional suggestion of the exact ratios of raw materials, often cited in historical literature, seems to be impossible. The glassmakers had to react to the variable composition of the raw materials, especially plant ash.     

A truly refractory crucible from fourth millennium Tepe Hissar, Northeast Iran

From the Early Chalcolithic to the Late Iron Age, melting and smelting crucibles were usually made from non-refractory ceramic fabrics, which required heating of the charge from within the crucible to avoid collapsing the ceramic itself. In this paper, an unusual melting crucible from Northeast Iran, radiocarbon-dated to the Late Chalcolithic (ca. 3600 BCE), will be presented that significantly changes our understanding of the development of technical ceramics in Southwest Asia. This crucible, made of a highly refractory talc-based ceramic held together by an outer layer of traditional non-refractory ceramic, is to our knowledge unprecedented at such an early date. As will be argued, this ancient crucible was heated from the exterior or from below and not from the interior. This method of firing, combined with the highly-specialized construction technique, makes this crucible so far unique in prehistoric metallurgy, and forces us to re-examine traditional models for the development of technical ceramics and metallurgical practices in the Old World.     

Lead isotope analysis as a new method for identifying material culture belonging to the Vázquez de Coronado expedition

Archaeological evidence has become an increasingly important component of efforts to identify the route of the Francisco Vázquez de Coronado expedition through northern Mexico and the southwestern United States (1540-1542). Here, we report the first high-precision lead isotopic measurements of artifacts from two archaeological sites with strong material evidence for the expedition’s presence: Piedras Marcadas Pueblo in New Mexico and the Jimmy Owens Site in Texas. The analysis of lead and copper armaments from both sites reveals that many artifacts have overlapping or extremely similar isotopic ratios. We propose that the narrow range of lead isotopic ratios measured on these artifacts can be interpreted as a geochemical fingerprint for some of the Coronado expedition’s surviving material culture, and provides evidence that we interpret to suggest the expedition derived lead and copper metal from Mexican sources. Such a geochemical fingerprint presents an empirical method for discriminating between artifacts that belonged to the Coronado expedition and those related to subsequent Spanish, historical, or modern activity in the Southwest U.S. Thus, this method could significantly impact the search for and identification of archaeological sites associated with the Coronado expedition.     

The coloured glass of Iulia Felix

Research on the cargo of glass in the Roman ship Iulia Felix, wrecked off the town of Grado (province of Udine, North Italy) in the first half of the 3rd century AD and composed of recycling cullet carefully selected for colour and type, provided much information on Roman glass production technology. A combined approach, involving analytical, statistical, and archaeological evidence, included chemical analyses (X-ray fluorescence, electron microprobe), which indicated that the coloured samples were all soda-lime-silica in composition, with natron as flux, although cluster analysis identified many compositional groups. Comparisons among the compositional groups of the colourless glass, previously studied, and those of coloured glass showed that the production technologies of the colourless glass vessels constitute two well-defined technological end-members, also related to group types, into which those of the coloured glass samples fall. In particular, coloured glass samples—all bottles, low-status vessels—were produced with mainly beach siliceous-feldspar-calcareous sand. However, unlike the colourless type, strict control of raw materials and decolourising processes was not adopted, and recycling was also practised, as demonstrated by the Sb₂O₃, Cu and Pb patterns. In this context, a “recycling index” (RI)—[(Sb₂O₃)_X/(Sb₂O₃)_Ref] * 100—is proposed here for the first time, in order to quantify the extent of recycling of antimony colourless glass in the batch. RI is valid for glass containing abundant Sb from an end-member of colourless glass. In conclusion, although it cannot be stated unequivocally that the identified compositional trends are related to different production centres or different raw materials, the strong evidence of compositional variability among all the Iulia Felix glass samples, both colourless and coloured, supports the dispersed production model for Roman glassware and the common practice of recycling in Roman imperial times, especially for low-status vessels.     

广州地区出土西汉青铜器矿料来源分析

广州地区出土汉代青铜器数量众多,在考古学方面研究成果不少,但通过科技考古研究其产地的却不多。为研究广州地区出土西汉青铜器矿料来源,通过对广州出土西汉青铜器进行成分分析和铅同位素比值测试,与广西、江西、云南、贵州、安徽、湖北、河南、河北、北京等地出土同时期青铜器成分进行比较,发现西汉中晚期各地青铜器合金配比情况基本趋同。且根据含砷等微量元素这一显著特征,认为与广西合浦出土同时期青铜器矿料可能来自同一个地方。测试的铅同位素比值高度集中,其矿料应该来自同一个地方。分别与广东、贵州、云南、陕西、河南等地战国至西汉青铜器铅同位素比值进行比对,发现与广东、贵州、云南出土青铜器矿料来源同属一个大的成矿区,与河南、陕西等地明显区别。验证了学者们在考古学研究认为岭南地区出土西汉青铜器产自本地的观点。     

特制绢地书画作品修复——以清代莫晋绢本书法立轴为例

特制绢地书画作品的修复历来是一大难题,因困于材料的特殊性与稀缺性,如寻觅不到同类补绢,就较难实现理想的修复效果。清代莫晋绢本书法立轴的画心材质为一种经过涂布、染色、描绘等工艺制成的特制绢本,因保存不当,画心已出现严重断裂残缺、部分涂层填料脱落等劣化现象,亟需修复保护。但画心用绢的质地和颜色特殊,无法找到与之接近的补绢。本次修复通过对绢的表面涂层进行检测分析,并参阅传统纸张再加工材料的检测报告和研究文献,再结合对材料的老化实验等,确定将瓷土和高岭土按一定比例混合来代替原涂层中的铅白作为本次修复的涂布材料。最后通过对修补涂层的全色,取得较为理想的修复效果。     

周陵贺家战国秦墓出土紫色八棱柱的科学检测

目前,对我国出土的紫色八棱柱形文物的研究内容主要集中在材质和制作工艺上,对其形制来源、功能用途等方面的系统论述相对较少。为探究周陵贺家战国秦墓出土的一件紫色八棱柱器物的表面特征、颗粒形态、材质成分、制作工艺等信息,利用超景深三维视频显微系统、偏光显微镜、X射线荧光光谱仪(XRF)、X射线衍射仪(XRD)、激光拉曼光谱仪(Raman)等分析方法进行了检测。并在此基础上对八棱柱形制的来源与演变、材质的来源、功能用途等方面进行初步推测,结果表明该紫色八棱柱微观形态为紫色和黄色晶体颗粒夹杂分布,主要成分为中国紫(硅酸铜钡),推测为二到三次烧制而成。通过文献查阅及梳理,推测八棱柱的形制受中国本土道家文化的影响较大,其主要功能为口含或窍塞。本工作对于我国出土紫色八棱柱的系统研究具有重要的借鉴意义。     

秦始皇帝陵园出土彩绘青铜水禽铜矿料来源探索

关于秦始皇帝陵出土彩绘青铜水禽铜矿料来源的研究,对进一步研究秦代的物质文化、青铜器冶铸工艺、装饰工艺以及铜矿来源均具有重要意义。本研究对部分秦始皇帝陵园出土彩绘青铜水禽基体进行了铅同位素分析及微量元素分析。并在此基础之上,与甘肃东部及关中西部出土的部分早期秦文化铜器、国墓地出土的部分铜器、周原李家铸铜作坊出土的部分铜器、山西中条山、江西瑞昌、江西铜岭、安徽铜陵以及湖北大冶铜绿山古铜矿以及秦岭山区的部分现代铜矿的相关数据进行了对比研究。结果发现,秦始皇帝陵园出土的青铜水禽使用了相同的矿料,且与绝大多数早期秦文化铜器所使用的矿料基本相同,但与国墓地以及李家铸铜作坊出土西周铜器的矿料明显有别。秦人使用的铜矿与秦岭山区现代铜矿较为接近,表明秦人的铜矿来源可能与秦岭山区有关。     

垣曲商城出土炉渣壁内金属颗粒及矿物组成的初步研究

采用偏光矿相显微镜、扫描电镜及X射线能谱分析等方法,研究垣曲商城出土炉渣或炉壁样品中主要合金元素Cu、Sn、Pb、As在炉渣中的分布及存在形式,同时分析了炉渣中主要物相的组成。结果表明,样品的主要结晶矿物有铜蓝或铜的硫化物矿物晶体、赤铜矿、孔雀石矿以及含有Co、Ni氧化物的短棒状或粒状结晶相;炉渣或炉壁中铜颗粒则以星散状或较大颗粒分布。Cu、As、Pb主要以合金颗粒的形态存在于炉渣巾,而锡则较多以四方柱状或针状氧化物骸晶形态存在于渣中;还有部分Cu、Pb存在于玻璃态渣相中。初步研究结果显示,出土炉渣炉壁的遗址属于冶炼、熔化或铸造工艺过程相关联的冶铸遗址,锡则是以金属锡在熔铜或铸造过程中加入。